help with different pose , animation and prespective in general

[almog99]

Hi there , im having really hard time creating character and then when i try to animate or even pose when he walking for example to different angle so he change from front view to side view and making it look like the same character exactly seems impossible to me ,same with animating to keep the legs for example same size all frames seems quiet hard sometimes its further from the view so it need to be basically smaller but how to know by how much to keep it look around the same size ?
any tips/guide about that ? 

Thanks.

[Rydin]

Here is a good read I recommend: https://design.tutsplus.com/articles/think-with-forms-not-lines-take-your-drawing-to-the-next-level--cms-24486